Preparation and Thermal Conductivity Study of Polyimide‐Based Graphene Films Doped With Sulfonated Graphene Oxide

With the iterative advancement of electronic devices, efficient thermal dissipation has become crucial for ensuring operational stability and service life, driving the demand for high‐thermal‐conductivity materials. Graphite films are ideal for heat dissipation due to their ultra‐high thermal conductivity and low thermal expansion. Polyimide (PI) is a promising precursor for such films owing to its aromatic‐rich structure and high carbon content. However, two major bottlenecks persist: pure PI films struggle to achieve sufficient molecular chain ordering during graphitization, limiting thermal conductivity enhancement; and the conventional use of graphene oxide (GO) to promote graphitization is constrained by high cost and agglomeration tendency. In this study, we introduce low‐cost, easily dispersible sulfonated graphene oxide (SGO) into a chemically imidized PI system to regulate molecular chain stacking. After graphitization, the resulting SGO‐PI film containing 2 wt.% SGO exhibits a superior thermal conductivity of 854.8 ± 26.1 W/(m·K), representing a 283.7% increase over pure PI films (222.8 ± 8.0 W/(m·K)) prepared via thermal imidization. This strategy offers a cost‐effective route for fabricating high‐performance PI‐based graphite films for thermal management applications, providing valuable reference for the development of thermal conductive films.